You can manually build the dio extension for your version of PHP, or install an older version of PHP that still bundled dio. It's not that hard to build it yourself, just a bit of a process, and it helps if you're on linux, and have a build environment... which I would assume you have if you are doing some kind of development that requires direct device I/O... Just get the dio source from the cvs repo, compile it, and then add the extension to your php configuration...